1. Field of the Invention
This invention relates to: a head cap which comes into close contact with a function liquid droplet ejection head as represented by an ink jet head of an ink jet printer so as to well maintain an ejection nozzle of the function liquid droplet ejection head, as well as a liquid droplet ejection apparatus provided with the head cap; a method of manufacturing a liquid crystal display device, a method of manufacturing an organic electroluminescence (EL) device, a method of manufacturing an electron emission device, a method of manufacturing a plasma display panel (PDP) device, a method of manufacturing an electrophoretic display device, a method of manufacturing a color filter, and a method of manufacturing an organic EL; as well as a method of forming a spacer, a method of forming a metallic wiring, a method of forming a lens, a method of forming a resist, and a method of forming a light diffusion body (or member).
2. Description of the Related Art
In the liquid droplet ejection apparatus of an ink jet printer, or the like, at the time of stopping the operation thereof, a function liquid which has been exposed to the air increases its viscosity to thereby cause the clogging at the ejection nozzles of the function liquid droplet ejection head. As a solution, the liquid droplet ejection apparatus is additionally provided with a cap unit which seals the nozzle surface of the function liquid droplet ejection head and which removes the function liquid whose viscosity has increased, by suction from the ejection nozzles. The cap unit is made up of: a head cap which comes into close contact with the nozzle surface of the function liquid droplet ejection head to thereby seal it; a lifting mechanism which moves the head cap toward, and away from, the function liquid droplet ejection head; and a suction pump which sucks the function liquid from the ejection nozzle through the head cap.
For example, in case the apparatus stops its operation for a long period of time, a so-called capping operation is performed by urging or pushing the head cap against the function liquid droplet ejection head to thereby prevent the function liquid from getting dried. At the time of resuming the operation of the apparatus, a so-called cleaning operation is performed by driving a suction pump in this state to thereby suck the function liquid. Depending on the apparatus, a so-called flushing operation (false ejection or waste ejection) is performed in which, while keeping the head cap slightly apart from the function liquid droplet ejection head, the function liquid is ejected from all of the ejection heads.
This kind of head cap to be used in maintaining (or performing maintenance work of) the function liquid droplet ejection head is provided with: a cap base which has formed a recessed groove on its surface; a function liquid absorbing material which is filed inside the recessed groove; and a sealing packing which seals the nozzle surface. The head cap has assembled therein an absorbing material urging (or pushing) member in order to push the function liquid absorbing material which may be swelled by sucking the function liquid.
The conventional absorbing material urging member is formed by thermally caulking the front end of a plurality of pushing projections which are formed integrally with the cap main body. In other word, by deforming the pushing projections which penetrate through the function liquid absorbing material at a plurality of points by means of thermally pressurizing deformation, the function liquid absorbing material is arranged to be held in position (see Published Unexamined Japanese Patent Application No. 2000-62202 and Published Unexamined Japanese Patent Application No. 2001-322296).
In the conventional head cap having the above-described construction, since the cap main body and the pushing projections are integrally formed, it is necessary, when the function liquid droplet absorbing material is to be replaced, to replace the entire head cap. In the applied art of the liquid droplet ejection apparatus, it is necessary to constitute the head cap by a corrosion-resistant material depending on the function liquid to be used. In such a case, it will be a waste of resources and cost to throw away once for all the entire head cap only to replace the function liquid absorbing material.